Improvement in clamps



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f f naar enea GEORGE -D.ILAMBERT, OF NEWv HAVEN, CONNECTICUT.l

Letters Patent No. 100,042, (lated March 8, 1870.

IMPROVEMENT IN CLAMPS.

The Schedule" referred to in these Letters Paltent and making part ol the same.

To all'whom it may concern Be it known that I, GEORGE D. LAMBERT', of New Haven, in the county of New Haven, and State of Connecticut, have invented a new and useful Improvement in Clamps; and I do hereby declare that the following is a full and exact description ofthe same, reference being had to the accompanying drawings and to the lettels of reference marked thereon.

Figure l is a side view of my improvement. Figure 2 is a longitudinal section ofthe same.

Figures 3 and 4 are detached views of the arm, to more clearly show its construction and operation.

This invention consists in providing the movable arm of an adjustable clamp with graduated teeth, for

the purposeof givingthe former a more perfecthold' tapering in shape, and upon its rear inside surface, serrations are placed, made deep 'at the bottom `to correspond with those ofthe beambut gradually diminishingin depth toward the upper end, until they die out entirely as shown in Iig.

Upon the opposite side of the beam A, a spring, E, is placed, operating upon the said beam, and let into4 the arm C in order to give it room to work. The object of this spring is to force and hold the teeth upon the beam A and Iarm C in their proper relative positions,

and prevent any liability of its being permanently de- 4 tached. v l This vcompletes the construction of my invention. The operation is as follows: `.After the clamp has been'placed upon the article, the arm C is pressed forward as far as possible, the spring E allows the seri-ations or teeth upon the arm to advance `over those upon the beam, so. that this is easily and readily performed, and when left at any given point, the arm is held by the. said spring and teeth rlnly to the beam at that point. The remaining deficiency between the arm and the work is taken up, and the proper pressure given by. means of the short screw I). To enlarge the capacity of the clamp, the arm is forced downward, as shown in fig. 3. This contracts the spring E, and throws out or Vdisconnects the teeth v upon the arm from those upon the beam, and while held in this position, the said arm may be moved backwardto any required point.

Iam aware that the serrated beam has been used for this purpose, and I do not consider it a part of my invention iuadjustable clamps. Where this beam is used, a plate, provided with corresponding serrations,

is placed within the arm, and is operated upon the s ame vby means of a nut or set=screw, this requiring nearly as much time and labor to prepare it for use as if it were not adjustable; and it is also objectionablefrom thefact that it is not certain. be cases where the points of the teeth wouldcome together and prevent the plate frombeing secured into its place, and the moment pressure was put upon it,-

it would slip. In my improvement, the spring E prevents the liability ofits'slipping, and the 4graduated teeth upon the arm allow it to be readilymoved backward in `lthe manner before stated.

I do notclaim a movable arm provided with teeth equal in size, for this I know to be old, but` Having thus fully described my invention,

Vihat I claim as new and useful, and desire to secuie by Letters Patent, is-

The movable arm C, when provided with graduatingteeth, as shown and described, for the purpose set forth.

This specific-ation signed and witnessed this 29th day of September, 1869. Y

' GEORGE D. LAMBERT.

Witnesses:

lUFUs H. SANFORD, FRANK Pnnscom'r.

There may` 

